Solder pastes are employed to form a solder joint, for example, in physically and electrically connecting components of a microelectronic package. A typical solder paste comprises a powder formed of a solder alloy which is dispersed in a liquid vehicle that contains a flux. One advantage of the paste is that it may be conveniently applied to the solderable surfaces of a printed circuit board (PCB), for example, by screen printing. The PCB is heated to melt the solder powder, whereupon the molten solder coalesces to form a liquid body sufficient to complete the connection. In order to obtain a strong bond, it is essential that the molten alloy flow in intimate contact onto the solderable surfaces, which phenomenon is referred to as wetting. Wetting is enhanced by the flux, which reacts to remove oxides from the metal surfaces. In a typical soldering step, fluxing occurs during the early stages of heating, so that the molten solder may readily wet the surfaces of interest. Nevertheless, the time for heating must necessarily be sufficient to not only melt the solder powder, but also to permit fluxing and wetting to be completed. Common solder paste typically includes a powder composed of a tin-lead alloy. During heating, the tin-lead alloy forms a liquid at about 183.degree. C. In order to accelerate heat transfer to the solder powder and thereby minimize the time at the elevated temperature, the assembly is typically exposed to an oven temperature that is as much as 40.degree. to 60.degree. C. above the solder melting point. This overheating significantly above the melting point tends to adversely affect electronic components. In order to avoid this, some have used solders of an indium-tin or bismuth-tin alloy to take advantage of low melting eutectic phases. However, such low temperature solder is not adequate to withstand operating temperatures experienced during many microelectronic applications. Thus, there is a need for a solder paste that permits soldering to be completed at a temperature suitable to avoid damage to microelectronic components, that minimizes the time required to melt the solder paste and wet the contact surfaces, and that provides a reliable solder joint for use at higher operating temperatures of modern day microelectronic packages.